Objective To evaluate the molluscicidal activities of three Chinese plants N. indicum Mill, P. stenoptera DC, and R. japonicum Houtt, and to clarify the molluscicidal mechanism. Methods N-butanol extracts and water ex...Objective To evaluate the molluscicidal activities of three Chinese plants N. indicum Mill, P. stenoptera DC, and R. japonicum Houtt, and to clarify the molluscicidal mechanism. Methods N-butanol extracts and water extracts of the three plants were obtained. The reactions of EST isozyme, glycogen and total protein of snails to the plant extracts were studied. Results EST electrophoresis showed that EST was an important antidotal enzyme system and reacted strongly to environment EST changed greatly during the whole exposure period so that it could be viewed as a pathological index of toxicity. Extracts decreased the glycogen content of the snails＇ soft tissues greatly, and also the protein content. ConcIusion All extracts show strong molluscicidal activity. The LD50 value of the water extract of N. indicum Mill is as low as 13.2 mg/L. EST can be viewed as a pathological index of toxicity. The energy metabolism abnormity is the key reason fnr the molluscicidal activities. The biochemical mechanism needs further research.展开更多
Ohjective To determine the visible light-induced photodegradation kinetics of two xanthene photosensitizers, phloxine B and uranine, in solution and on the surface of silica TLC plates, and to examine the phototoxicit...Ohjective To determine the visible light-induced photodegradation kinetics of two xanthene photosensitizers, phloxine B and uranine, in solution and on the surface of silica TLC plates, and to examine the phototoxicity of residues of degradation, which could provide valuable safety data on the two photosensitizers and other xanthene chemicals when applied in the environment. Methods UV-Vis absorption during photodegradation was monitored with a Unico 2102 spectrophotometer. Organic content of samples was measured with a Shimadzu TOC 4100. Phototoxicity tests were carried out using Saccharomyces cerevisiae with the methods modified from Daniels. Results When phloxine B and uraniue degraded in solution, their apparent rate constant k was 0.0019 and 0.0027 min^-1, respectively. The total organic carbon （TOC） content decreased by approximately 50% during the 8 h irradiation period, which led to a gradual decrease in phototoxicity of the residues. The photodegradation of photosensitizers on the surface of silica TLC plates was much faster than that in the solution. The apparent rate constant k and the half life of phloxine B were 0.0073 min^-1 and 95 min, respectively. Conclusion Visible light can rapidly induce photodegradation of phloxine B and uranine. The phototoxicity of residues is also decreased. The environmental risk of applications of phloxine B and uranine is minimal.展开更多
基金This work was supported by the National Natural Science Foundation of China (No. 30471506).
文摘Objective To evaluate the molluscicidal activities of three Chinese plants N. indicum Mill, P. stenoptera DC, and R. japonicum Houtt, and to clarify the molluscicidal mechanism. Methods N-butanol extracts and water extracts of the three plants were obtained. The reactions of EST isozyme, glycogen and total protein of snails to the plant extracts were studied. Results EST electrophoresis showed that EST was an important antidotal enzyme system and reacted strongly to environment EST changed greatly during the whole exposure period so that it could be viewed as a pathological index of toxicity. Extracts decreased the glycogen content of the snails＇ soft tissues greatly, and also the protein content. ConcIusion All extracts show strong molluscicidal activity. The LD50 value of the water extract of N. indicum Mill is as low as 13.2 mg/L. EST can be viewed as a pathological index of toxicity. The energy metabolism abnormity is the key reason fnr the molluscicidal activities. The biochemical mechanism needs further research.
基金the National Natural Science Funds with contract No. 30471506the "Eleventh Five-Year Programme" Science and Technology Foundation of Forest with contract No. 2006BAD03A15
文摘Ohjective To determine the visible light-induced photodegradation kinetics of two xanthene photosensitizers, phloxine B and uranine, in solution and on the surface of silica TLC plates, and to examine the phototoxicity of residues of degradation, which could provide valuable safety data on the two photosensitizers and other xanthene chemicals when applied in the environment. Methods UV-Vis absorption during photodegradation was monitored with a Unico 2102 spectrophotometer. Organic content of samples was measured with a Shimadzu TOC 4100. Phototoxicity tests were carried out using Saccharomyces cerevisiae with the methods modified from Daniels. Results When phloxine B and uraniue degraded in solution, their apparent rate constant k was 0.0019 and 0.0027 min^-1, respectively. The total organic carbon （TOC） content decreased by approximately 50% during the 8 h irradiation period, which led to a gradual decrease in phototoxicity of the residues. The photodegradation of photosensitizers on the surface of silica TLC plates was much faster than that in the solution. The apparent rate constant k and the half life of phloxine B were 0.0073 min^-1 and 95 min, respectively. Conclusion Visible light can rapidly induce photodegradation of phloxine B and uranine. The phototoxicity of residues is also decreased. The environmental risk of applications of phloxine B and uranine is minimal.
